1. Diagram this argument. Since Mary visited a realtor and her
7-1
Diagram this argument.
Since Mary visited a realtor and her
bank’s mortgage department, she
must be planning on buying a home.
Step 1. Number each statement
and note each indicator word.
Since (1)Mary visited a realtor and (2) her
bank’s mortgage department, (3) she
must be planning on buying a home.
Go to next slide.

2. Step 2. Which of the claims is the conclusion? Which are premises?
7-2
Since (1) Mary visited a realtor and (2) her bank’s mortgage department, (3) she must be planning on buying a home.
Step 2. Which of the claims is the conclusion? Which are premises?
(1)
(2)
(3)
Premise.
Note the
indicator word,
“Since.”
Premise.
Conclusion.
Go to next slide.

3. Step 3. Use arrows to represent the intended
7-3
Since (1) Mary visited a realtor and (2) her bank’s mortgage department, (3) she must be planning on buying a home.
Step 3. Use arrows to represent the intended
relationship between the claims.
(1)
(2)
In this case the premises are independent. Even though the combined force of both premises makes the argument stronger, either premise could stand alone in supporting the conclusion.
(3)
Go to next slide for another example

4. Argument Diagramming Sample #2
7-4
Argument Diagramming Sample #2
Sandra can’t register for her classes on Wednesday.
After all, Sandra is a sophomore and sophomore
registration begins on Thursday.
Step #1. Identify each claim and note any indicator words that might help identify premise(s) and conclusion(s).
(1) Sandra can’t register for her classes on Wednesday. After all, (2) Sandra is a sophomore and (3) sophomore registration begins on Thursday.
Go to next slide.

5. “After all” is generally a premise indicator.
7-5
“After all” is generally
a premise indicator.
(1) Sandra can’t register for her classes on Wednesday. After all, (2) Sandra is a sophomore and (3) sophomore registration begins on Thursday.
This “and” serves to join
two different claims.
Go to next slide.

6. These are dependent premises since both (in conjunction) are
7-6
Step #2. Use arrows to show the relationships between the claims in the argument.
Decide whether
the premises are
independent.
Or dependent.
(2)
(+)
(3)
(2)
(3)
(1)
These are dependent premises
since both (in conjunction) are
necessary to prove the conclusion.
(1)
For another example go to the next slide.

7. 7-7
Pool maintenance can cost hundreds of dollars a year and we really don’t have that kind of money. So, I don’t think we should put a pool in this summer. Besides, pools pose a real drowning danger to small children.
Step #1. The first task is to analyze the argument. Decide what the various claims are and begin to decide which are premises and which are conclusions. Number the claims and note any indicator words.
Go to next slide.

8. 7-8
Note the “and”
connecting two
claims.
(1) Pool maintenance can cost hundreds of dollars a year and (2) we really don’t have that kind of money. So, (3) I don’t think we should put a pool in this summer. Besides, (4) pools pose a real drowning danger to small children.
A premise
indicator.
“So” is a
conclusion
indicator.
Go to next slide.

9. Step #2. Use arrows to represent the argument.
7-9
Step #2. Use arrows to represent the argument.
Premises 1 and 2 are
dependent. While premise 1 could stand alone, premise 2 can’t.
(1)
(+)
(2)
(4)
Premise 4 is independent.
It could be offered alone as
support for the conclusion.
(3)
Go to the next slide.

10. 7-10
(1) Pool maintenance can cost hundreds of dollars a year and (2) we really don’t have that kind of money. So, (3) I don’t think we should put a pool in this summer. Besides, (4) pools pose a real drowning danger to small children.
(5) We don’t want dangerous things in the yard.
(1)
(+)
(2)
Notice that there is an implied premise here working in conjunction with #4. Do you see it?
(4)
(+) (5)
(3)
For another example, go to the next slide.

11. means money, you should write a check to PBS immediately.
7-11
You’ve often complained that mainstream television doesn’t have quality programming so I think you should support public broadcasting. Besides, you watch PBS all the time and fair is fair. Since support
means money, you should write a check to PBS immediately.
Step #1. As before, concentrate on analyzing the various claims. Use numbers to identify them and note any indicator words.
Go to the next slide.

12. 7-12
This argument is more complex, but the same skills apply. What is the intended conclusion of the argument? How do the various parts of the argument work to provide support for this conclusion?
(1)You’ve often complained that mainstream television doesn’t have quality programming so (2) I think you should support public broadcasting. Besides (3), you watch PBS all the time and (4) fair
is fair. Since (5) support means money, (6) you should write a check to PBS immediately.
Go to the next slide.

13. 7-13
You can start diagramming from anywhere. Keep trying different arrangements until your diagram best represents the intended meaning of the argument.
The indicator “so” shows claim 2 to be a conclusion and 1 seems to support this conclusion.
(1)
(3) (+) (4)
Claims 3 and 4 offer another reason that 2 is true.
(2)
Go To Next Slide

14. 7-14
(1)
(3) (+) (4)
(2)
(+)
(5)
What about claims 5 and 6? The “since” before 5 marks this as a premise but for which conclusion? Context and experience tell us that this is a premise supporting claim 6.
Claim 2, which says you should support PBS, combines with claim 5 which defines support as money, to support the final conclusion 6.
(6)
End of Tutorial